Understanding Voiding Cystourethrography Images: For the Pediatrician

Voiding cystourethrography, or micturating cystourethrography is a fluoroscopic imaging of the lower urinary tract to assess the bladder, urethra, and vesicoureteric reflux (VUR). It is the diagnostic modality of choice for detecting VUR and is also indicated in children with prenatally diagnosed hydronephrosis, bladder outlet obstruction, urinary incontinence, neurogenic dysfunction (spinal dysraphism), workup posturinary tract infections, and congenital anomalies in the genitourinary tract. PROCEDURE Feeding tubes of sizes 5-F and 8-F are used for infants <3 months and older children, respectively. A scout image (plain precontrast image of the kidney, ureter, and bladder region) is first taken, following which diluted water-soluble iodinated contrast media are instilled into the bladder. At the early filling stage, the minimally distended bladder is imaged in anteroposterior (AP) projection, to rule out lesions such as ureterocele or bladder tumor. Both AP and steep oblique image are obtained at full bladder state. If reflux is observed, the ipsilateral renal fossa is imaged before voiding. For imaging during voiding, a single AP image usually suffices for urethral assessment in girls; however, in boys, right and left oblique projections are obtained for complete urethral evaluation. The postvoid image must include bilateral renal fossa. In high-grade reflux, delayed imaging (15 minutes postvoid) is done to differentiate simple reflux from obstruction-related reflux.Image 1: (a) Normal voiding cystourethrography in the male. (a) Full bladder (blue arrow) with contrast opacification on anteroposterior view. (b and c) Right (b) and left (c) oblique micturating images show prostatic urethra (yellow arrow), membranous urethra (red arrow), bulbar urethra (green arrow), penile urethra (purple arrow) and bladder in both the images (blue arrow). Prostatic and membranous parts comprise the posterior urethra, while bulbar and penile parts form the anterior urethraImage 2: Normal voiding cystourethrography in the female. (a) Full bladder (blue arrow) with contrast opacification on AP view. (b) Lateral micturating image shows normal female urethra opacification (green arrow). Urethrovaginal reflux of contrast, which is considered a physiological variant with no clinical significance, is demonstrated (red arrow) and bladder (blue arrow). Multiple congenital spinal anomalies (orange arrows) are marked in image (a)Image 3: International reflux system grading. Grade I – Reflux into ureter; Grade II – Reflux into nondilated ureter; Grade III – Mildly dilated ureter and pelvicalyceal system; Grade IV – Tortuous ureter and dilated pelvicalyceal system. Forniceal angles are blunted; Grade V – Markedly dilated ureter, pelvicalyceal system, and tortuous ureter. Forniceal angles, papillary impressions are obliteratedImage 4: Vesicoureteric reflux. (a) Gross dilatation of bilateral renal collecting systems and ureters with ureteric tortuosity – Grade V reflux (blue arrows). (b) Bilateral Grade V reflux with associated intrarenal reflux (yellow arrows)Image 5: Neurogenic bladder. (a) Voiding cystourethrography of a 9-year-old girl shows a vertically elongated urinary bladder (red arrow) with an irregular trabeculated wall (green arrow), giving a Christmas-tree appearance, and multiple oval-shaped diverticula arising from the posterior wall of the bladder (black arrow). Reflux reaching up to the pelvicalyceal system (aqua arrow) – Grade III vesicoureteric reflux. (b) Christmas-tree appearance with irregular bladder wall (green arrow) with reflux into the ureter – Grade I vesicoureteric reflux (blue arrow)Image 6: Posterior urethral valve. (a) Valve as a band/shelf-like linear filling defect in the posterior urethra (orange arrow) with the dilated upstream urethra (blue arrow) and bladder neck hypertrophy (yellow arrow). (b) Shelf-like linear filling defect in the posterior urethra (orange arrow) with secondary pressure changes in the bladder, in the form of trabeculations and multiple small contrast-filled outpouchings s/o diverticula (green arrow). Abrupt change in urethral caliber is noted at the level of the valve. There is bladder neck hypertrophy (yellow arrow) marked in both images 6 (a) and (b). Distally, the anterior urethra appears normal in the course, caliber, and outline. (c) Posterior urethral valve (blue arrow) with dilated posterior urethra, multiple tiny bladder diverticula, and Grade V vesicoureteric reflux (orange arrow)Image 7: (a and b) Left oblique and lateral image shows a contrast-filled outpouching (green arrow) arising from the posterior wall of the bladder – bladder diverticulum. Posterior urethral valve (orange arrow) and bladder neck hypertrophy (purple arrow) are noted in image (a)Image 8: Multifocal urethral strictures. Images (a) and (b) show multifocal segments of narrowing in both anterior and posterior urethra (multiple orange arrows), in a 7-year-old male patient. The most common causes of multifocal urethral strictures include urethritis, trauma, and instrumentationImage 9: Posterior urethral diverticulum/prostatic utricle in a case of posterior urethral valve. Voiding right oblique image, (a) shows a saccular contrast-filled outpouching projecting posterolaterally from the prostatic urethra, showing contrast retention on the postvoid image, (b) which is consistent with a posterior urethral diverticulum or prostatic utricle. Note is also made of the dilated prostatic urethra, irregular outline of the bladder wall, and bladder neck hypertrophy, which are suggestive of the diagnosis of posterior urethral valveDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.